280 ON DEMODEX PHYLLOIDES. 



towards the base and periphery of" the gland, head downwards. 

 That the mites are air-breathers is apparent from the little 

 bubbles constantly forming under the cover-glass from specimens 

 recently pressed out of a gland. 



As the whole of the herd observed by Csokor (22 animals) were 

 attacked by the Demodex, he considers that its transference from 

 pig to pig is evidently more easily effected than is the case with 

 D. canis. The explanation of this is to be sought for in the dirty 

 habits of the pig and uncleanly condition in which they are kept. 



Fig. 



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EXPLANATION OF THE PLATE. 



-Ripe egg of D. phylloides. 



-First ecdysis : head with rudiments of jaws and ocelli ; crenate 



outline of thorax due to the developing extremities ; granules 



posteriorly may be urinary concretions. 

 -First 6-footed larva ; appendages of head already well advanced ; 



6 short feet. 

 -Second ecdysis : the jaws in the form of four rods, larval case 



striped posteriorly. 

 -Eight-footed nymph ecdysis beginning posteriorly. 

 -Last ecdysis, within the larval skin is the fully developed mite. 

 -D. phylloides : male, ventral aspect — the small fissure near the 



front of the ventral surface of the abdomen is the anus, in front 



of this two folds represent the penis. 

 -Female, ventral aspect — the abdomen contains an egg undergoing 



segmentation ; genital and anal fissure behind the sternum. 

 -Female, lateral aspect — the crenate outline towards the dorzal 



surface of the thorax is the contour of the stomach ; the egg 



inclines towards the genital fissure ; the transverse striping of 



the abdomen is seen to stop abruptly at the thorax. 



